Control system



May 28, 1946. -M, E, REAGAN ETAL 2,401,017

CONTROL SYSTEM 'Fileduune 2?, 1944v 2 sheets-sheet -1 WITNESSES:

May 28, 1946. M E REAGAN UAL A ZL? f CONTROL SYSTEM Filed June 27, 19442 sheets-sheet' 2 n KY/"- fr Y. LATTORNE Patented May 28, 1946 MauriceE. Reagan and Willard A; Derr, Wilkinsburg, Pa., assignors toWestinghouse Electric Corporation, East Pittsburgh, Pa., a corporationofPennsylvania Application June 27, 1944, Serial No. 542,294'

s claims, (Cl. 1774353) Our invention relates, generally, to supervisorycontrol systems, and it has reference, in particular, to control systemsfor controlling from a central control station, and providingindications `of the operating position of, apparatus which is locatedremotely from a remote supervisory con-r trol station.

Generally stated, it is an object of our invend tion to provide asupervisory control system which is simple and inexpensive tomanufacture, and which is flexible and positive inoperation.

More specifically, it is an object of our invention to provide forremotely controlling and super` vising the operation of apparatus whichis positioned some distance from a remote supervisory control stationover a single supervisory and control conductor between the apparatusand remote station.

Another object of our invention is to provide for extending asupervisory control system to include apparatus whichgis relativelydistant from the remote station without requiring an excessive number ofadditional conductors or equipment.

It is also an object of our invention to provide for controlling anautomatic reclosing circuit breaker at a location which is relativelydistant from a remote supervisory control station and for indicatingwhether the circuit breaker is open and subject to reclosing, lockedopen, closed, or whether the control and supervisory channel between thecircuit breaker and the remote supervisory control station is inoperating condition.

4 Yet another object of our invention is to provide for utilizingafpluralityof point supervision oontrol relays in conjunction with apair-of supervisory control-relays for effecting operation andsupervision of a circuit breaker remotely located from a remote controlstation over a single conductor and at the same time maintainvsupervision' of the conductor so as to obtain an indication whenthe'conductor is shorted, grounded or open. Still another object of ourinvention is to provide for maintaining supervision of the condition ofa control and indication'channel between an operating station and acircuit breaker remotely located therefrom, as well as effectingoperating:

station is effected over a single supervisoryconf trol conductor whilemaintaining supervision of the operating condition of the conductor. Apair of supervision control relays are used to provide a plurality ofdifferent stopping circuits for the counting chain at the remotestation. Selective operation ofthe supervision control relays iseffected by having a pair of point supervision relays connected to thesource of control voltage in cascade with a supervisory controlconductor extending intermediate the relays of the pair to the remotecircuit breaker location. Auxiliary switch means are provided at theremote circuit` breaker location for controlling the polarities appliedto the control conductor in accordance withth'e position of the circuitbreaker, thereby selectively controllingthe positions of pointsupervision relays. Failure of the control conductor results in jointoperation of the point supervision relays associated therewith, so as toprovide for indicating a conductor fault. Control of the circuit breakeris effected over the saine conductor, the circuit breaker control meansAbeing non-operative on` the relatively small currents used by thesupervision control relays.`

For a more complete understanding of the nature and slope of ourinvention, reference may be made to the following detailed descriptionin connection withthe accompanying drawings which, when joined togetherwith Figurel at the left and Figure 2 at the right, provide adiagrammatic tively distant from a remote supervisory control view of asupervisory control system embodying the principal features of theinvention, in which: Figure 1 is a diagrammatic view of the centralcontrol station apparatus,

Fig. 2 is a diagrammatic view of the remote station apparatus togetherwith the auxiliary equipment used at the remote circuit breakerlocation; and

Fig. 3 is a diagrammatic view of a control and indicating systemembodying the invention in another of its forms.

The preferred embodiment of our invention is shown and described hereinas applied to the supervisory control system disclosed in the BoswauPatent No. 2,091,301 issued August 31,J 1937,

and assigned to the assignee of the present invention. For thepurpose ofsimplification, most of the elements of the system of the Boswau patentare shown herein in the same cooperative rela- `tion as in the Boswaupatent and bearing the same reference characters as in the Boswau patentdrawing. Certain relays, conductors and other elements of structurehavebeen omitted, and others have been added, and certain relay contactelements have been added to the relays of the Boswau patent in order toperform different functions. These elements have been designated byreference characters, not found in the Boswau patent. Since no changeswere made in the control station coding, selecting, and controlapparatus, shown in Fig. 2 of the Boswau patent, this portion of thesystem has been shown boxed in Fig. 1 with the same conductorsconnecting it to other portions of the system, as shown in the` Boswaupatent. changes were made in connection with the circuit breaker controlrelay lill` of Fig.'4 of the Boswau patent, the substation coding,selecting, `and control apparatus of Fig. 4 thereof hasV been shownherein as boxed in Fig. 2 with the circuit breaker control relay 4M,illustrated as boxed therein, in orderto show the changed circuitconnections.

While it is common to control remotely located circuit breakers from acontrol station by a supervisory 'control system such as that shown inthe Boswau patent hereinbefore referred to, the circuit breakers, thuscontrolled, are usually located relatively close to the supervisorycontrol apparatus at the remote station. Hence, it is usually noproblemto provide the necessary control and supervisory circuit between thesupervisory apparatus and the circuit breakers. However, in manyinstances the circuit breakers to lbe controlled by means of asupervisory control system are not all located close to a singlelocation but are scattered over a relatively wide area. One example ofthis situation is in the case of the power supply to a subway systemwherein the circuit breakers may be scattered along the length of thesubway line. In such case it becomes necessary to select one or moreremote control stations for the supervisory control system and thenfurther provide for extending the supervisory control system from theremote stations to the individual circuit breaker locations.

Referring to Fig. 2 of the drawings, the reference numerals 500 and 502may denote generally circuit, breaker locations which may be relativelydistant from the remote control station and the rest of the supervisoryand control apparatus shown in the ngure. The circuit breakers (notshown) at these locations may be of the auto matic reclosing type and ofthe non-reclosing type respectively, in order to illustrate thedifferent features of the invention.

In order to provide for extending the operation of the supervisorycontrol equipment from ythe remote substation to the circuit breakerlocation at 552 where a non-reclosing circuit breaker may be located, asingle supervisory and control conductor 553 may be provided inconnection with the circuit breaker location 552 which may be designatedas point i on the supervisory control system where it may be desired tocontrol and supervise the operation of the circuit breaker associatedwith that point, andat the same time maintain `supervision of thecontrol conductor 553.

In order to provide for indicating not only when the circuit breaker isopen or closed but also whether the supervisory control conductor 503 isfree from faults, the supervision control relays 551 and 508 may beadded to the system of the Boswau patent. These relays have a pluralityof contact members cooperativeto provide a plurality of differentstopping circuits for the point selecting relays 353 through 358 of thecounting chain at the remote station. tact members may be added to therelays 355 and Additional con! Since only relatively minor 351, ln orderto provide additional stopping points for the chain. f

Control of the supervision control relays 55? and 558 may be eiTected bymeans of a pair of point supervision relays 559 and 5m, which alsocontrol the operation oi the point relay 3l3, and which may be connectedin cascade across the common source of direct current control voltage soas to be normally operated to the energized position. A connection maybe provided from therebetween to the supervisory control conductor 553so that either one or the other of the point ysupervision relays may beshunted down and the other picked up, depending on the polarity .of :thecontrol voltage applied to the supervisory control conductor 553.

The polarity ofthe supervisory control conductor 553 may be varied byconnecting the circuit breaker end thereof to either negative orpositive polarity through either the tripping relay 3I9 or the closingrelay 320 by means of an auxiliary circuit breaker switch 32|. For thisreason the connections of the circuit breaker control relay M4 may bechanged by adding an additional armature 53| for placing negativepolarity on the closing relay 325 to operate it.

In order to providefor electing operation of the point supervisionrelays without `at the same time operating either of the tripping or theclosing relays, the point supervision relays may be disposed to operateon relatively small control kcurrents which are insui'icient to operatethe tripping or closing relays. The resistance of the point supervisionrelays may be suihciently high, so as to limit the control currenttherethrough to a value less than that required for operating either ofthe tripping or closing relays.

Where the circuit breaker at the remote location is provided withautomatic reclosing means so that the circuit breaker will reclose aftertripping due to a fault, it will be necessary for the operator at thecentral control station to know not only whether the circuit breaker isopen or closed, but Whether it is open and subject to reclosing by theautomatic reclosing means upon the removal of the fault or whether it islocked open. This indication is necessary so that the `operator may knowwhether it is safe for a repairman to Work on circuits controlled by acircuit breaker which is open.

In order to provide this additional indication and also maintainsupervision of the control rchannel between the lcircuit breakerlocation and the remote substation, a pair of supervisory controlconductors 5i2 and 5l3 may be provided lbetween the circuit breakerlocation 550 and the remote station. At the remote station, two pairs ofcascade connected point supervision relays 5l 5, 5|5 and 5H., 5l8 may beprovided in connection with the supervisory control conductors 512 and5l3, respectively. Associated make-and-break contacts of these pointsupervision relays may be interposed in the energizing circuit of thepoint relay 3H to provide for dcenergizing it upon a change in theoperating condition of any one of the point supervision relays.Additional contact members may be provided on the point supervisionrelays for providing diierent control circuits for the supervisioncontrol relays 501 and 508 which determine the different stopping pointsof the counting chain, comprising` relays 353 through 308.

In order to provide for selectively operating the point supervisionrelays 5I5 through 5l8 in accordance with the condition of the circuitbreaker and the supervisory control conductors, an auxiliaryswitch 3|8'on the circuit breaker at the remote'location 500 may be utilized forconnecting either positive or negative polarity to the lsupervisorycontrol conductor 5|3, depending on' whether the circuit breaker is openor closed. The auxiliary switch 3|8' may also beused to connect one oranother of the terminals ofthe closing relay 3|1 to the positive ornegative ter.-` minal of the source. i j For thepurpose ofsupervisingwhether` or not the circuit breaker is merely open and subject toreclosing upon the removal of a fault condition, or whether it is lockedopen, a circuit breaker control switch 520 may be used for controllingthe connection of the supervisory control conductor 5|2 to eitherpositive or negative polarity throughltheIoperating Winding of the triprelay 3|6. The circuit breaker control switch may be of toggle or latchtype having tripand close operating windings 522 and 523, respectively,for operating the armature 524' to either the trip or close positionwherein it remains until operated to the other position. i

The circuit breaker may be locked out by operating the circuit breakercontrol'switch 520 to the trip position whereupon the reclosing circuitfor the circuit breaker-may be interrupted by the opening of contactmembers 520 at the same time a supervisory signal is sent to the controlstation in a manner which will be described hereinafter.

In order to provide for supervision of the additional functions at thecentral control station, the'lamp relays |28 and |30 of the BosWaupatent at points and 4 `may be replaced by associated pairsof lamprelays |28', 'I2-8", and |30' and |30", respectively. Additional contactmembers may be added to the point selecting relays |40, |4|, |142 and|43 and an extracontact may beadded to the signal relay |32 in order toprovide for selectively 4controlling the operation of these point lamprelays to' light both the red and green lamps when the supervisorycontrol con-n ductors between the circuit breakers and the remotestations are subject to afault condition. In the case of the circuitbreaker at location 500 which is designated as point on the system, thepoint lamp relays also perform the additional function of lighting anamber lamp 526 when the circuit breaker is open but not locked open.`

Referring to Figs. 1 and 2, it will be seen that theapparatus associatedwith the circuit breaker at the location 500 is shown for the closedposition ofi the circuit breaker with the point supervision relays 5|5and 511 up and the point supervision relays 5|6 and 5|8 down. Thecircuit breaker control switch 520 is in the close position.Accordingly. the point lamp relay |28' at the control station is up,providing an energizing circuit for the red lamp |03 which indicatesthat thecircuit breaker is closed. Should the circuit breaker open dueto afault condition, the auxili'ary switch 3|8 moves to the openposition, connecting the supervisory control conductor 5|3 to thepositive terminal through the operating winding of the closing relay3|1. Thepoint supervision relay 5|1 is thereby shunted down and thepoint supervisionfrelay 5|8 picks up momentarily interrupting theholding circuit for the point supervisory relay 3| I, deenergized.

An energizing circuit is thereby provided for the substation startingrelay (not shown) of the substation coding, selecting and control appairatus. The counting chain starts to pulse and which drops and remainssends out -twopulses or one control pulse to select point v| :at .thecentral control station, relays 303, 302, 304, 30| .picking up insequence, andrelays303, 302 dropping out. At this point a stoppingcircuit forithe chain is provided` from the substation coding,`selecting and control apparatus through conductor 521, armature 528 andback contact offthefpointsupervisory relay 3| and front contact andarmature 529 of the point selecting relay'304 toreffect energization ofthe stopping relayfof` the substation control apparatus: f N `1` i. i Atthe central control station, thepoint selectingrelays |33, |31,l39 and|36 pick up and relays` |38,` |31, dropout in synchronism with therelays 303, 302, 304and 30| of the remote station.' An'energizingcircuit for the alarm |05 is provided bythe alarm relay |21 which picksup and the point selecting relay |38 picks up and rings until therelease key |03 is depressed. When relay |36 picks up, an energizingcircuit is thereby` provided for the point relay |33 at point fromnegative through the operating winding of relay |33, front contact andarmature 530 of point selecting relay |39, conductor 53| through frontcontact and armature |65 of sequence relay |36, back contact andarmature |66 of sequence relay |35, back contact and armature |61 ofsequence relay |31, to positive in the control station coding, selectingand control apparatus. Point relay |33 picks up and establishes anenergizing circuit for the check lamp |01 through armature 532.

After a short delay when the receiving control relay ofthe coding,selecting and control apparatus of the control station drops, anenergizing circuit is established for starting the control stationcounting chain to pulse and check the point selection operation. Relays38, |31, |39 and |36 pick up in sequence, relays |38, |31 dropping outas soon as the relay |36 picks up. At this point a stopping circuit isestablished through front contact members and armature 530 of pointselection relay |39 and front contact members and armature 533 of the'point relay |33 to stop the chain from further pulsing,

At the remote station, relays 303, 302, 304 and 30| pick up in sequence,relays 303 and 302 dropping out when relay 30| picks up. An energizingcircuit is thus `established for the point relay 300, extending from thenegative terminal through the operating winding of relay 309, frontcontact and armature 534 of 4point selection relay 304, front contactsand armature 334 of sequence relay 30|, back contact and armature 335 ofsequence relay 300, back contact and armature 336 ofsequence relay 302to the positive terminal in the remote station coding, selecting andcontrol apparatus.

Point relay 309 in picking up sets up a circuit which starts the remotestation counting chain pulsing to supervise an indication of the changedposition of the circuit breaker. Due to point supervision relay 5| 1dropping and point supervision relay 5|8 picking up, the energizingcircuit -for the supervision control relay 501 is intercounting chain`at the remote. station from pulsing' aftery two rcontrol kpulsestosignal that the circuit breaker is` open butnot locked out.

Atthe same time negative polarity is placed on Ythe pointsupervisoryrelay 31| through front contactand armature 352 Vof relay 35|',conductor 54|, armature 543 and front contact of the point relay` 303,and the armatures and Acontacts of the point supervision-relays 5.15,516, 511 and 518. At the central control station, the counting chainpulses in synchronism with the remote station chain, and at the secondcontrol pulse, an energizing circuit is, established ,for the lampcontrol relay |32 whichpicks up. .This puts positive volt-age on thepoint lamp relay |28', through armature 502v and front contact of pointselecting relay |40, armature 543 and front contact i of the lamp.control relay |32, and armature 544 14| land .sequence-relay |35 pick upto provide a vstopping circuit from positive through arma.- ture 506'and front contact of the point relay 133,'armature 550 and back contactof the point supervisory relay |29, contact spring H2 and outer :contactmember of the control key |10, conductor |19-andconductor 455|'throughfront contact anda-armature |90a, of the point selection relay` 14|.

At the remote station, counting chain relays 303, 302 through 306, 336,334 and 335 pulse in synfchronism with the relays of the control stationproviding an energizing circuit for the cirand iront contact of thepoint relay |33, dropping V it and extinguishingv the red lamp. At thesame time positive voltage isput on the point lamp relay |28" througharmature 545 and front contacts of the point selectingrelay |40,armature 17|! and front contact of the lamp control relay |32, armature543 and i'ront cont-acts of the point relay |33, dropping the point lamprelay |28" and completing an energizing circuit for the amber lamp 526which indicates that the circuit breaker isropen but not locked out. Thegreen lamp |13 is extinguished due to its energizing circuit beingopened when the point lamp relay 1 20" drops. After a predetermined timedelay, the supervisory control system automatically restores itself tothe deenergized or normal condition,

In order for the operator tc lock the circuit f.

breaker at location 500 open and make it safe for a -repairman to Workon the circuits controlled thereby, the operator must go through amanual tripping operation, rst turning the twist key |10 to tripposition so that springs and |12 engage their outer contacts, anddepressing the point key |14 which shunts the individual point relay |29through spring |15 and establishes an energizing circuit through spring|16 for starting the central control station counting chain to pulse.Relays |38, 1-31, |39 and |36 pick up in sequence, relays |38 and |31dropping out when relay |33 picks up, to send out a selection code ofone control impulse. An energizing circuit is thereby providedfor'stopping the selection Code through armature 541 and front contactmembers -oi the point relay |29, and front contact members and armature548 of the point selection relay |39.

At the remote station, the point selection relays 303, 302, 304 and 301pick up and relays 303, 3512 drop out in synchronism with the relays138, |31, |39 `and |35 of the controlstation, providing an energizingcircuit for thepoint point relay 309 associated with the circuit breakerat location 500. vAfter a predetermined time delay, the relays 303, 302,300 and again pulse to send a check code 'of one control impulse andcheck the selection of the point relay 309. At the control station therelays 38, |31, |39 and 13:` pulse and the point relay |33 picks up,lighting the check lamp |01 when the check code is received.

v The operator then depresses the master control key |02 closing contact10|, which starts the countingchain pulsing to send out three operationVcontrol pulses 'for operating the circuit breaker control switch to thetrip position. 'Ihe counting chain of the control station stops at threecontrol impulses when point selection` relay Yrelay 315 .picks up andestablishes an obvious energizing circuit for the trip winding 522 ofthe circuit breaker controlswitch 520, which operates to the tripposition and opens Ycontact members 520a to interrupt thereclosingcircuit of the circuitbreaker and lock the circuit breaker out.

A positive Voltage is thereby placed on the supervisory control'conductor 5|2 V'through contact members, 520e, dropping pointsupervision relay 515 andpickingup point supervision relay 511, so thatsupervision control relay 501 is now up, and supervision control relay508 is down. The changed position of the point supervision relays 515and 516 interrupts momentarily the energizing circuit for the individualpoint relay 311 so that itdrops and starts the remote station counting`.chain pulsing to rsend a supervision code. vThechain pulsesuntil-positive voltage is put on the stopping relay through the frontcontacts ofv supervision control relay 501, back contactsof supervisioncontrol relay 508 and front contacts and armature 354 of point selectionrelay 3.06. Three control impulses are thus sent to indicate that thecircuit breaker is open and locked out.y

At the control station, the relays |38, |31, |39 and |36 through |41pick up and drop out in synchrcnism with the relays of the remotestation counting chain, providing an energizing circuit for the signalcontrol relay |32. The relay 32 in turn' places positive and negative onthe point lamp relays |28. and 128"'respectivelythrough armatures 503and |11 of the relay |32 and armatures .180 and 551 of point selectionrelay 14| respectively. The point supervision relay |29 is also pickedup by negative polarity being applied through armature |14 of relay |32and armature 553-and front contact of the point relay |33.

The point lamp relay |28 stays down and the point lamp relay |28" picksup. The circuit for the amber lamp 525 is interrupted by armature 550which engages its front contact and places positive polarity on thegreen lamp, indicating that the breaker is open and locked out so thatit is safe to work on the circuits associated therewith.

Closure of the circuit breaker may be effected over the supervisorycontrol system inthe -usual manner, rst depressing` the point key |10 toselect poi-nt I, then operating the twist key |10 to the close position.and depressing the master key |02',` The circuit breaker control relay414 is operated :in` response to the close code of ve control impulses`and negative polarity is applied to the operating winding of the closingrelay 3H over thesupervisory control conductor 5|3. The circuit breakercontrol switch 520 is thereupon actuated to the close position and thecircuit breaker is closed. The usual supervisory signals are sent andthe indications of a closed breaker appear at the central controlstation.

Should either or both of the supervisory control conductors 5|2 or 5|3have a fault thereon, being open, grounded or shorted, the controlvoltage will be removed from either or both of the point supervisionrelays 5|5, 5|6 or 5| 1, SIB.

Both of the relays of the pair from which the voltage is removed willoperate to the energized position. Accordingly, the individual pointrelay 3| I is dropped to start the remote station counting chain pulsingto select the proper point at the control station. Subsequently, due tothe fact ,that both of the supervision control relays 501 and 508 willbe deenergized, a supervisory signal ofiour controlimpulses will besentto indicate an open wire or a fault thereon. y

At the control station, the alarm relay `|2'| operates and both thepoint relay |33 and the signal control relay |32 will energize in order,so that energizing circuits will be established for both of the pointlamp relays |28" Vand |28 through front contact members and armatures543Vand |1| of the signal control relay, and front contacts andarmatures 562 and 503, respectively, of the point selection relay |42.Accordingly, both the red and green lamps will be lighted, indicating anopen supervisory control line condition. 'I'he disagreement lamp |08will also be lighted, regardless of whether the control key l I0 isinthe close or trip position, throughthe armatureand front contact ofeither point lamp relay |20",l or |28'.

`In connection with the circuit breaker location 502, which may, forexample be denoted as point 4 Vonthe supervisory system, it will beobserved that the singlepair of point supervision control relays 509 and`5|0 are selectively operable'depending on the polarity applied to .thecontrol, conductor 503 or the absence thereof, to energize either thesupervision control relay 501, or both of the supervisioncontrol relays501 and` 508, or to deenergize, both of them, in order to provide threedifferent stopping circuits for the remote station counting chain. Sincethe circuit breaker. at location 502 is not arranged for automaticreclosing, these operating positions of thesupervision control relaysmay be used to in' dicate that the circuit breaker is tripped, that itis, closed, or that there is a faultysupervisory controlconductorcondition. The circuit breaker trip and closing relays are` likewiseoperated over the supervisory control conductor under the control of thecontrol relay M4 and the auxiliary circuit breaker relay 32 `At thecontrol station, the point lamp relays and |30" associated with point 4operate in substantially the'same manner as the point lamp relays |20'and |28 of point to control the operation of the associated indicatinglamps, except that an amber lamp is not provided, and the redand greenlamps are used in the usual manner to merely indicate whether thecircuit breaker is closed or open. Since this type of supervisorycontrol `circuit is used on circuitrbreakers not having automaticreclosing, the additional indication of whether the circuit breakerislocked out is not necessary since there isvno danger of the circuitbreaker reclosing due to the removal of a fault condition whiletherepairman is working on the circuits.

Supervision of the single supervisory and control conductor is providedin the same manner as set forth in the description in connection withthe circuit breaker at location 500. When the control voltage is removedfrom` the conductor 503, bothv of the point supervision relays 509'and5|0 operate. Both of the supervisory control relays 501 and 508 arethereby deenergized, and a code of four control impulses is sent toindicate a faulty condition on the conductor. 1

It will be apparent from the above description and from Fig. 3 of lthedrawings that the extended portion of the supervisory control scheme mayin itself comprise a useful subcombination Where it is-desired tooperate and eiect an operating condition of remotely located apparatuswithout using the supervisory and control equipment of the Boswaupatent, In such instance the control conductor 503 may be used inconjunction with a manual control switch555 which maybe operated'toapply either a negative or a positive control voltage to the singlesupervisory and control conductor 503 for selectively energizing thetrip or close relays 3 I9 or ,320 at a remote circuit breaker location.

Supervision maybe effected by means of green and red signal lamps 5B1and 568 which may be connected to the common source in cascade andprovided with an intermediate connection to the supervision and controlconductor 503, or they may be controlled by the point supervision relays509and 5|0 similarly connected.` i Accordingly, with the circuit breakeropen and positive potential applied to the supervisorycontrol conductor503, pointsupervision .relay will be up and the green lamp 568 `will belighted. The

breaker may be closed by` moving the switch 565 o to apply negativepotential to the conductor 503, thus energizing the close relay 320. Theauxiliary circuit breaker switch operates and appliesnega- From theabove descriptionand accompanying l drawings, it will be apparent thatwe have provided a new and novel manner for supervising and controllingcircuit breakers or other apparatus units which are located remotelyfrom a remote supervisory station, and at the same time providing forsupervision of the supervisory control conductors extending between theremote` station and the circuit breaker location. This extension of thesupervisory control system provides positive supervision and control oftheremotely located circuit breaker and may be used apart from thesupervisory control system for effecting operation of apparatusatfremote locations and-obtaining an indication thereof without thenecessity of the usual supervisory coding equipment. i

Since certain changes may be made in the above described construction,and different embodiments of the invention may be madewithout departingfrom the spirit and scope thereof, it is intended that all matter`contained in the above description` or shown in the accompanyingdrawings should be considered as illustrative and not in a limitingsense.

We claim as our invention: y

1. In a supervisory control system having a plurality of control pointsat a remote station associated With apparatus located'remotely therefromand selectively controllable from a central control station over asupervisory control channel, a chain of counting relays at each stationcooperative to select a point to be controlled or indicate an operationof the apparatus associated with said point and check saidoperation, asingle control and supervision conductor extending from the remotestation to the apparatus location, means at the apparatus'locationnormally effective to maintain one polarity or the other on theconductor depending on the condition ofk the apparatus, means at theremote station selectively responsive to either polarity or the absencethereof on said conductor Vtofprovide different stopping circuits forthe remote station counting chain at different points in the operatingsequence, and means at the VcontrolV station controlled by the countingchain thereat for indicating the condition of the apparatusand ofthe'supervisoryand control conductor.V v

2. A supervisory control system for an apparatus unit distantlypositioned from a remotestation comprising, supervisory and controlapparatus including a chain'of counting relays locatedV at each of acontrol station and the remote station operable in synchronisrn inresponse to changed conditions at either station, a single supervisoryand control conductor extending' from the apparatus unit position to theremotev station, auxiliary switch means responsive to the apparatus unitposition 'for normally maintaining either positive or negative polarityon said conductor depending on the' position of the apparatus unit, andcontrol means at the remote station normally responsive to the polarityof the conductor to provide different stopping circuits for they remotestation counting chain to effect an indication of the apparatus unitposition and furtherresponsive to the absence of either polarity n theconductor to provide a still different stopping circuit for the remotestation counting chain to effect an indication of a faulty supervisoryand control channel.

3, A supervisory control system comprising, su-

pervisory control means including'a chain of relays at each of a remoteand a control station operable in synchronism over a single supervisorycont-rol channel in response to an initiating signalr from eitherstation, supervision control means operable to provide differentstoppingcircuits for the chain, of relays at the remote station, a pairof point supervision relays. controlling the operation of thesupervision control means, a single supervision 'and control channelconnecting the point supervision relays toa circuit breaker locationremoved from the remote station, circuit means at the remote stationproviding operating circuits for the point supervision relay means toeffect operation of the supervision control means to provide indicationof a faulty supervision and control. channel, and means normallyresponsive to the position of the circuit breaker to apply either a.positive or a negative control potential to the supervision and controlchannel to render one or another of the point supervision relaysinoperative andI effect an indication of the circuit breaker position.

fri The combination in a supervisory control system havingsupervisorycontrolV apparatus at remote and control stationsv includinga chain of counting relays at each station operable in synchronism totransmit or receive coded series of impulses, of supervisory controlmeans at the remote station operable to stop the remote station countingchain rat a plurality of diierent points, a pair of point supervisionrelays providing a plurality of circuits for the supervisory controlmeans, said relays being normally connected in cascadeL to a source ofcontrol voltage for providing operation of the supervision control meansto effect a predetermined supervisory code signal, and a singlesupervisory control conductor associated with a circuit breaker and thepoint super- Vision relays for jointly applying either a positive or anegative control voltage to the point supervision relays in accordancewith the position of the circuit breaker to shunt one or another of themand operate the supervisory control means to effect one or another ofdifferent predetermined supervisory code signals to indicate the circuitbreaker position.

5. In a supervisory control system having supervisory control apparatusat remote'and'control stations each with a chain of counting relaysoperable from either station in synchronism to control and indicate theposition of an apparatus unit located distantly from the remote station,a pair of supervision control relays selectively operable to provide aplurality of stopping points for the remote station counting chain, asingle supervisory and control conductor extending from the remotestation to the apparatus unit location, means at the apparatus unitlocation for applying control potentials of opposite polarities to theconductor depending on the position of the apparatus unit, and a pair ofpoint supervision relays operable in response t0 the-polarity of thecontrol conductor to effect operation of the supervision control relaysto indicate theap'- paratus unit position, said relays being connectedin cascade to a source of control voltage for effecting operation of thesupervision control relays .to indicate a conductor fault when thecontrol voltage on the control conductor is rendered ineffective at theremote station.

6. A supervisory control system comprising, supervisory and controlequipment located at remote and control stations including a chain ofcounting relays at each station operable in synchronism from eitherstation, a circuitybreaker located remotely from the remote station-,asingle supervisory and control conductor extending from the remotestation to the circuit breaker,

lmeans at the circuit breaker location operable toV apply controlvoltages of opposite polarities from a source to the control Vconductordepending on whether ther circuit breaker is open or closed, a pair ofpoint supervision relays connected to the source of control voltage andvto the control conductor so as to be jointly operable when th'e controlvoltage on the'control conductor is reduced below a predetermined valueand selectively operable depending on the polarity of the controlvoltage on the control conductor when it is above the predeterminedvalue, a, plurality of supervision control relays operable under thecontrol of the point supervision relays for controlling the remotestation Vcounting chain to produce diierent code signalsI dependingonthe positions of the point supervision relays; and indicating means atthe controlstation operable under the control of the control stationcounting ch'ain to indicate Whether' the circuit breaker is open orclosed or Whether there is a fault on the control conductor.

7. A supervisory control system comprising, supervisory controlequipment located at remote and control stations including a chain ofcounting relays at each station operable in synchronism from eitherstation, a plurality of supervision control relays at the remote stationoperable to provide a plurality of stopping circuits for the countingrelays at the remote station for indicating dilerent conditions of thesystem, a cir,- cuit breaker having means for automatically reclosingafter tripping due to a fault and located remote from the remotestation, supervisory tripping and closing means of the control. systemVassociated with a circuit breaker located remote from the remote stationand having means for effecting automatic reclosing after tripping,switch means associated with the circuit breaker for connecting oneterminal of the closing means to one terminal of a direct current sourcewhen the circuit breaker is closed and the other terminal of the closingmeans to the other terminal of the source when th'e circuit breaker isopen, control switch means operable under the control of the supervisorytripping and closing means to control the tripping and closing circuitsof the circuit breaker and connect one terminal of the supervisorytripping means to one or the other terminals of the source depending onwhether the control switch' is in the trip or the close position, asupervisory control conductor extending from the other terminal of eachthe supervisory tripping and closing'means to the remote controlstation, and a pair of point supervision relays for each conductor saidrelays being connected in cascade across the source and havingconnections intermediate the relays of one pair to one control conductorand intermediate the relays of the other pair to the other conductor.

8. A supervisory control system comprising, supervisory controlapparatus located at remote and control stations and connected by asupervisory control channel, said apparatus including a chain ofcounting relays at each stai-,ion operable in synchronism from eitherstation, supervisory tripping and closing means operable over thesupervisory channel for a circuit breaker distantly located from Itheremote station means operable to automatically reclose the circuitbreaker subsequent to a fault condition, control means operable inresponse tooperation of the supervisory tripping means to preventreclosing thereof by the automatic reclosing means, a supervisorycontrol conductor extending from each of the supervisory tripping andclosing means, means associated with the control means and the circuitbreaker for connecting the conductors to one or the other terminals of adirect current source depending on whether the control'means and thecircuit breaker are in Vthetrip or closed position, and a pair ofcontrol relays associated with each control conductor cooperative topro- Yvide different stopping circuits for the remote station countingchain to produce dierent supervisory code signals for eiectingindications at the control station depending on whether the circuitbreaker is merely open, locked open or closed, and whether the controlconductors have a faul-t condition thereon.

i MAURICE E. REAGAN.

WILLARD A. DERR..y

